1. Field
This invention relates to sights useful with archery bows. It is more specifically directed to such a sight which is adaptable for use from both elevated and level shooting positions.
2. State of the Art
Bow sights of varying designs have been suggested for use with archery bows. The sights are useful as an aid for determining the proper trajectory of an arrow being shot by an archer. One problem to an archer in the field is to determine the proper trajectory for arrows shot at varying distances. It is important to an archer, once approximating the distance of the shot, to be able reliably to launch his arrow in a trajectory which allows for the normal drop of the arrow over the distance of a shot.
Sights have been developed which provide various beams or sight-point locations for use depending upon the estimated distance of the target. Typical such sights are disclosed by U.S. Pat. No. 2,788,701. U.S. Pat. No. 3,013,336 discloses a sight which determines the degree to which the bow is tipped to secure a desired curved trajectory. With experience, the archer determines the degree necessary for a particular distance and can accurately reproduce that degree of tip for subsequent shots. Conventionally, a bow is regarded as normally held vertically with respect to the earth. "Tipped forward" refers to positioning the upper limb of a bow forward of a vertical reference line, the lower limb being positioned behind that line (toward the archer). The opposite respective positioning of the limbs is regarded as tipping the bow backward.
The problem of an accurate sighting is increased for archers shooting from elevated positions such as from a tree stand. A class of sights commonly known as pendulum sights has evolved to assist archers shooting from elevated positions. An example of such a sight is disclosed in U.S. Pat. No. 4,120,096. According to that patent, a pivoting sighting element carries a number of sight beads spaced along a single row. The sighting element is weighted so that in an unlocked condition, it will assume an approximately horizontal position without regard to the attitude of the archery bow. In locked condition, the sighting element is held approximately vertically, and the individual beads are used for sighting at various distances in conventional fashion. Windage (azimuth) adjustment is possible for the entire sighting element, but not for individual beads.
Individually adjustable pin sights are disclosed in connection with vertical sights by U.S. Pat. No. 4,449,303.
None of the bow sights currently available to archers is completely satisfactory in all circumstances. A number of disadvantages, such as noise of operation, persist when pendulum-type sights are used. Inconveniences and inaccuracies are associated with the calibration of such devices, especially in the field. Because field conditions are often rigorous, the maintenance of typical bow sights in their adjusted condition is problematic. There remains a need for an improved sight which is rugged and reliable under field conditions, provides the benefits of multiple-pin sights for distance shots as well as the benefits of pendulum sight for shots from elevated positions, andn provides for azimuth adjustment of the individual beads used for distance shots.